Vents for batteries have generally been included in batteries having containers of substantially structural integrity. Thus, alkaline cells and cells having pressurized components have generally been constructed in metallic cylindrical containers which are capable of withstanding excessive high build-ups and which containers embodied substantial mechanical vents if such internal pressure become sufficiently high to break the intgrity of the seals or walls of the container.
Cells and batteries have been constructed in less rugged containers such as in foil packaging but generally only if the components of the electrochemical system of the individual cells are not detrimentally subject to gassing. Any low pressure gassing in such cells has however been difficult to control while also preventing ambient air and moisture from entering the battery container and in maintaining the integrity thereof. Alternatively, reliable low pressure vents are bulky and not generally suitable for use in thin film battery enclosures such as foil enclosures. In addition, reliable vents have not been economical to manufacture and include in these cells or batteries.